Closed hydronic systems need a minimum pressure to stay active at all times. In order to keep it running smoothly, hydronic system feeders must be installed in any hydronic heating systems. Canarsee offers a few options that differ in water capacity, psi, and use. PressurePal series are intended for use with standard hydronic systems such as radiant heating and snow melting systems. SolarPal series are designed for use in solar heating systems with static pressure at 25-35 psi range. They are also suitable for higher-head hydronic/radiant/snow melt systems.